Lenny was out at the street one morning when he saw a rare sight: a car that has wheels with spokes driving down the road. As he jogged closer for a good look, he noticed the spokes on the top were going so fast they were blurred. But when he looked at the bottom half of the wheel, the spokes appeared to be going so much slower he could have counted them. If all the spokes were on the same wheel, how did this happen?

Hint

Answer

When viewed by a stationary object, the top spokes seem to be zipping by because they are going the speed of the car plus the rotation speed. But the spokes on the bottom of the wheel are going the opposite direction as the car, which is moving the same speed, but in the opposite direction, appearing still.Hide